# Copyright 2019 Xilinx Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import yaml

def load_config(config_file):
    with open(config_file, 'r') as stream:
        try:
            parsed_yaml = yaml.safe_load(stream)
        except yaml.YAMLError as exc:
            msg = 'An error occurred during YAML parsing.'
            raise ValueError(msg)
    
    if not isinstance(parsed_yaml, dict) and not isinstance(parsed_yaml, list):
        raise ValueError('The source is not a YAML mapping or list.')

    if isinstance(parsed_yaml, dict) and len(parsed_yaml) < 1:
        raise ValueError('Could not find any element in your YAML mapping.')
    
    return parsed_yaml